HOW GUN-BARRELS ARE MADE. 229 



which this is accomplished, ought to be seen to be 

 duly appreciated. This trouble is only taken with the 

 best barrels. In the manufacture of barrels of an 

 inferior description, the ends of the rods are cut in a 

 sloping direction, and, when welded together, become 

 quite square at the part where the pieces are joined. 

 In a finished barrel the points of junction are easily 

 recognized. By tracing the twist, a confusion will be 

 found to exist for about an eighth of an inch, every 

 six or seven inches ; and from this appearance you 

 may conclude that, for a barrel so joined, the welder 

 had not the best' price. Having joined the whole of 

 the spirals, three inches are again heated to a welding 

 heat, the mandril is introduced, and the tube ham- 

 mered, in a groove, to the size required. This opera- 

 tion is repeated until the whole length is finished. 



Then follows hammer-hardening : that is, beating 

 the barrel, in a comparatively cold state, in a groove, 

 with light hammers, for the space of half an hour. 

 This is a most important part of the process. It 

 closes the pores, condenses the texture of the metal, 

 compresses a greater substance"' into less bounds, in- 

 creases greatly the strength of the barrel, and renders 

 it more elastic. Yet this is seldom done, unless spe- 

 cially requested; and then a gratuity is, of course, 

 expected either in money or been A few pots of the 

 juice of Sir John Barleycorn will infuse more strength 

 into your barrels than you could purchase for ten 

 times the amount in money ; as they have the effect 

 of making the hammers descend with increased 

 velocity." 



